Technical Field
The invention relates to a power control technique. Particularly, the invention relates to an electronic apparatus having a power saving effect.
Related Art
As the issue of global warming is gradually taken seriously, awareness of environmental protection gradually rises, and consumer electronic apparatuses related to power consumption (for example, desktop computers, notebooks, mobile phones, digital cameras, and tablet personal computers, etc.) all take power saving as an important target, and are designed towards a trend of achieving maximum performance with limited power.
A general consumer electronic apparatus generally has an embedded controller (EC) to execute power management of the electronic apparatus. In computer technology domain, the EC can also be implemented by a keyboard controller. The EC can be connected to various components in the electronic apparatus, and the EC performs operations by using an alternating current (AC) power or a low voltage auxiliary power generated by a direct current (DC) power received from a battery. The EC also monitors an operation/power consumption state of each component in the electronic apparatus, and accordingly adjusts the power required by each of the components to achieve an effect of controlling power consumption.
However, since the EC is in charge of power management in the electronic apparatus, it is required to immediate react in response to the state of the electronic apparatus, and the EC has to be kept activating permanently in design. In other words, even if the electronic apparatus has entered a power saving state (for example, a standby mode or a shutdown state), the EC still operates based on an auxiliary power to continually consume power, so that the power of EC cannot be saved.